//定位上下左右居中

@mixin ctp($width, $height) {  
	position: absolute;
	top: 50%;
    left: 50%;
    margin-top: -$height/2;
    margin-left: -$width/2;
}

//宽高
@mixin wh($width, $height){
	width: $width;
	height: $height;
}

@mixin scrollBar {
	::-webkit-scrollbar-track-piece {
		background-color: transparent;
	}
	::-webkit-scrollbar {
		width: 7px;
		height: 7px;
		background-color: transparent;
	}
	::-webkit-scrollbar-thumb {
		border-radius: 5px;
		background-color: hsla(220, 4%, 58%, .3);
	}
}